<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function copyUrl(o) {
            o.site = "http://www.baidu.com"  // ?

            var p = new Object();
            p.site = "https://www.baidu.com" // 这个
            o = p;
        }

        var obj = {} //
        copyUrl(obj)

        console.log(obj.site) // 
    </script>
</body>
</html>